Greg Daniels wanted to get Mackenzie Crook, Martin Freeman, and Lucy Davis from the original British Office series to appear in the episode {The Convention} as their respective characters (Gareth Keenan, Tim Canterbury, and Dawn Tinsley), but was unsuccessful due to scheduling conflicts.

In the episode {Diwali}, Michael proposes to Carol to no avail. However Carol is played by Steve Carell's wife, Nancy.

On the episode {Diwali}, the roles of Kelly's parents were played by Mindy Kaling's real life parents.

In {Gay Witch Hunt}, the kiss between Michael and Oscar in the conference room was not scripted. The scene had been shot a couple of times with Steve Carell not kissing Oscar Nuņez. Then on one take, Oscar saw "[Carell's] lips coming closer and closer". Nunez recalled "I'm like, 'Dear God, he's going to kiss me.' And sure enough, he planted one on my face." The other cast members were laughing during the kiss but because the camera stay focused on Carell and Nunez, the scene was still usable.

It is frequently mentioned that the characters Phyllis Lapin Vance and Michael Scott are the same age, having gone to high school together. In real life Phyllis Smith is 11 years older than Steve Carell.

In order to get permission to use the song "Your Body is a Wonderland" in {A Benihana Christmas}, [?] John Mayer asked that he be given a Dundie.

In {A Benihana Christmas}, Creed is singing "Spinnin N' Reelin", a song that he wrote himself. Creed Bratton is a musician as well as an actor, and has released some albums.

John Krasinski was forced to cut his hair for his role in Leatherheads, so he was forced to wear a wig for the latter half of season 3.

For the big anger scene in {The Return}, Ed Helms actually bloodied his knuckles while punching the wall, something that took five or six takes.

On {Phyllis' Wedding}, [?] Davey Faragher, bassist for Elvis Costello's band, [?] The Imposters, performs the role of bass player in wedding band, Scrantonicity. The band name itself is a play on words of an album by [?] The Police, titled [Synchronicity]. During the reception at Phyllis' Wedding the songs they are shown playing are covers of songs by [?] The Police.

The blouse worn by the stripper during the party in {Ben Franklin} is a previous shirt Jenna Fischer wore as Pam last season.

On {The Job}, when Jim came back from New York and asked Pam out for a dinner, Jenna Fischer didn't know that was happening. The crew wanted to surprise her that her character, Pam, will finally go on a date with JIm.

Joss Whedon directed the episode {Business School} with a subplot involving Jim transforming into a vampire. Whedon also created [Buffy the Vampire Slayer]. His vamp mythology is borrowed heavily in this episode. He later went on to direct The Avengers and The Avengers: Age of Ultron; [?] John Kransinski was poised to be cast as Captain America before Chris Evans was chosen.

Although Pam is skeptical in {Traveling Salesmen} to get coffee with Angela due to their hatred/likeness for one another, in real life Angela Kinsey and Jenna Fischer are best friends.

Michael apologizes to Oscar, after he finds out he's gay, for calling him a homosexual slur--but his apology outs Oscar to the entire office. And Jim decides to take a promotion at the Stamford office.

Micheal and Dwight go to a convention in Philadelphia and run into Jim, and Michael becomes jealous of Jim's relationship with his new boss. Meanwhile, Pam gets ready for her first date since her engagement.

Michael is in trouble once again as Jan busts him for declaring it's "Movie Monday" where everyone watches a movie and neglects work. Angela pushes Dwight to make a move on Michael's job while Pam and Jim find creative ways to waste time.

Michael encourages the entire Scranton branch to support Kelly and attend a local celebration of Diwali, the Hindu Festival of Lights. Meanwhile, Andy convinces Jim to turn a late night of work into a drinking game.

When Jan tells Michael that the Scranton Branch will be shutting down, Michael strives to keep his staff's spirits up. Meanwhile, everyone privately begins to envision how their lives will change in the aftermath.

Jan informs Michael that the Scanton branch of Dunder Mifflin will be merging with the Stamford Branch. Jim and Pam are reunited while the other employees of both branches must adjust to their new co-workers.

Trouble among the members of the party planning committee results with the office having two competing Christmas parties, but Michael isn't interested in celebrating because he has just broken up with his girlfriend.

Dwight does a favor for Angela to keep her from getting in trouble. Andy finds out and uses it against him to get in tighter with Michael. Now Dwight must fess up, which will reveal his relationship with Angela, or risk getting fired.

Andy does the impossible--he makes everyone in the office miss Dwight, who is forced to take a job at Staples. Meanwhile, Oscar comes back to the office and Michael predictably throws a stereotypical Mexican party to celebrate.

Michael asks Jim to get a male stripper for Phyllis's office bachelorette party, but he gets a Ben Franklin impersonator instead. Meanwhile, the men's bachelor party goes as planned until Michael becomes uncomfortable with the stripper.

Michael is a guest speaker for Ryan's business class, but they have a falling-out after Michael finds out that Ryan spoke negatively about Dunder-Mifflin. And back at the office, Dwight tries to kill a bat that he found in the ceiling.

While Michael and Jan go to their first Dunder Mifflin outing as an official couple, the office workers left behind go out for happy hour. During happy hour, Roy finds out that Jim and Pam kissed at Casino Night.

Dwight saves Jim from an attack by Roy, but Dwight won't allow Jim to thank him for it. Meanwhile, Darryl asks Michael for a pay raise, and Michael discovers that he is woefully underpaid--so Michael goes to headquarters to ask for one himself.

Andy returns to the office after weeks of anger management training, determined to make a fresh start with all the Dunder-Mifflin employees. Meanwhile, it's safety training day in the office, and Michael and Dwight are on a mission to illuminate the dangers of the workplace.

Michael tries to be proactive during a watermark crisis, but only makes the situation worse. Meanwhile, Angela has trouble being apologetic with customers, and Andy discovers a secret about his new girlfriend.

Phyllis gets flashed in the parking lot, and Dwight goes all out to secure the premises. Michael ostensibly takes the women in the office to the mall to comfort them, but he's really doing it to get advice about breaking up with Jan.

Michael appoints Dwight as regional manager, anticipating that he will receive the job at corporate. Jim and Karen also interview for the same position. And Michael gets back together with Jan after she gets a boob job.